Can't get armature to move mesh!
First, you needed to join all parts of the deer by selecting the misc ones, then the main one, and keying Ctrl + J.

You also needed to parent the mesh to the armature by first selecting the mesh, then the armature, and keying Ctrl + P. You would select Armature Deform > With Automatic Weights.



Lastly, some weight painting had to be done. I did all of this. Here is the finished .blend file: